kksonakiya thats is not really true.
The galaxy note 10.1 will work wonders for digital sketching AND painting.
It might not messure up to the intuos5 or the latest cintiq but the device does have a quad core 1.4 GHz processor based on the arm9-chip and the pressure sensativity messures up to 1024 levels.
Saying you can not draw stuff like the picture above on it with apps like SKP or layerpaint (best app btw) is stupid, for example look at this:
To me this is better then the picture above.
If you are are just starting out or if you want something more portable then cintiq, intuos5 or the heavy laptop convertibles then go with the Galaxy note 10.1 (if you want android) or if you want windows for fullblown proffesional style cintiq like quality go with the Samsung 7 slate series!
One last thing: Dont depend to much on the devices or tools you are using to sketch, draw or paint. Learn it as a skill be versitile in your application.